WASHINGTON (AP) — Steve Bannon’s attorney relayed questions, in real time, to the White House during a House Intelligence Committee interview of the former Trump chief strategist, people familiar with the closed-door session told The Associated Press.

As lawmakers probed Bannon’s time working for President Donald Trump, Bannon’s attorney Bill Burck was asking the White House counsel’s office by phone during the Tuesday session whether his client could answer the questions. He was told by that office not to discuss his work on the transition or in the White House.

It’s unclear who Burck was communicating with in the White House or whether it was top White House lawyer Don McGahn, who Burck is also representing in special counsel Robert Mueller’s investigation into contacts between the Trump campaign and Russia.

The conversations were confirmed by a White House official and a second person familiar with Bannon’s interview. They spoke on condition of anonymity because they were not authorized to speak publicly.

Bannon refused to answer a broad array of queries from the House Intelligence Committee about his time working for Trump, leading the committee chairman to authorize a subpoena.

Lawmakers were expecting a similar fight Wednesday with Trump’s White House as another senior aide, Rick Dearborn, appears for a private interview with committee.

The developments brought to the forefront questions about White House efforts to control what current and former aides tell Congress about their time in Trump’s inner circle, and whether Republicans on Capitol Hill would force the issue.

It is unlikely the committee will face the same White House objections with Trump’s former campaign manager, Corey Lewandowski, who is also being interviewed Wednesday. He never served in the White House.

The interview with Lewandowski and Dearborn were confirmed by two people familiar with the committee’s work who spoke to the AP on condition of anonymity to discuss the confidential interviews.

The congressional subpoena came the same day The New York Times reported that Bannon, a former far-right media executive and recently scorned Trump adversary, has been served with a grand jury subpoena issued by special counsel Robert Mueller.

Bannon confirmed that he had received the subpoena from Mueller during his House Intelligence Committee interview, according to a person who spoke to the AP on condition of anonymity because they weren’t authorized to publicly discuss Bannon’s interactions with Mueller.

Bannon is the highest-ranking person who served in the Trump White House to receive a grand jury subpoena. The move by itself doesn’t indicate that Mueller is presenting evidence to the grand jury to support future criminal charges. It could also signal that Mueller is seeking to pressure Bannon to agree to an interview with his investigators.

Lawmakers questioned Bannon as part of their investigation into Russian election inference and sought answers about Trump’s thinking when he fired FBI Director James Comey.

But Bannon refused to answer questions about that crucial period, and as a result, the chairman, Rep. Devin Nunes, R-Calif., issued the subpoena, spokesman Jack Langer said.

A White House official said the White House counsel’s office had a conversation last week with committee counsel about Bannon’s testimony and was told the questions were expected to be about the campaign. The official said the White House offered to send an attorney to attend the interview and was told the move wasn’t necessary.

But when the lawmaker’s questions moved to Bannon’s time in the White House, Burck, his attorney who also represents White House counsel Don McGahn, got on the phone with the counsel’s office. The official wouldn’t say who Burck spoke with in the counsel’s office or whether it was his client, McGahn.